LG 39LN575s Backlight Repair, No Picture, LED Blinks 3 Times, Power Supply & Boards Check Help

Hello, as in the topic I have my TV set for repair with damaged backlight. After repairing the backlight, I regenerated the tape and it was ok.
It worked for a few days and I do not know if it was an earlier or now defect, the backlight works and does not display the image.
After correcting the tapes, at least I think so, he got up for one more day, I thought it would be ok, so I corrected the tapes, I folded it, it worked day and suddenly it died again.
The backlight rises, the red diode blinks three times and then there is no image, startup logo or anything else in further work.
The tested power supply looks ok. The boards respond to voltages, but we do not have a picture, I do not know where to look.
The patient is waiting for your help
What to measure to facilitate diagnosis.

hmmm Samsung 39LN575s Interesting ....
I do not know such a Samsung model.
Lg it is.

AdamQuatro wrote:

The tested power supply looks ok

Just by eye?

AdamQuatro wrote:

the plates react to the voltage but

What?

Hello, thank you for the improvement, I was distracted by my wife yesterday and thought about LG and entered the phone brand.
I correct and count on support.
The power supply gets up because the backlight works, the power LED blinks red 3 times and goes out but there is no picture.
No bulging capacitors when it comes to eye checking, but I don't mean to prove who is the best, where to start the measurements and where to look for the fault.
When I was young, this website worked in its further development, people blasphemed more than they helped.
I am not a specialist, so I ask where to put the meter and what to check, what to pay attention to to find a solution to the problem.
Thanks in advance with a serious reply.

You have the voltage values on the laminate.
If they are correct, check F1 first.
And don't demonize, because you are probably still distracted.

on Saturday I will have more time to sit in the workshop and measure everything on tapes

>>17005617 У меня было такое, возьми провер на маличие холодной пайки по шине 12 вольт в блоке питания. Проверь наличие 12 вольт в блоке питания на разьеме подключения шлейфа идущего на MB/